Getting started with 3-tier architecture in VB.net

I recently started developing a project in 3-Tier architecture, with a BLL, DAL, and Presentation layers. The references I used were sample 3-tier applications off the net, and all of them di开发者_StackOverflow中文版ffer from each other. So, now i am confused which one is the correct 3-tier.

Could you please be kind enough, to point to a proper tutorials or book, which is following the correct 3-tier architecture, so that I could follow it.

look at this article article

in 3 tier architecture there are:

1. DAL Repository classes
2. BLL Services classes
3. PL Controllers classes

I had the same problem when I was learning about architecture of .NET applications in C# language. It is normaly then 3-layer (layer and tier has other meaning) aplications are different. I think the best theory you get from book Professional ASP.NET Design Patterns by Scott Millet. Scott describes BLL, DAL and the most frequently used patterns on these layers. When you start with developing .NET applications I recommend you learn about ActiveRecord pattern that is easy to learn.

3-tiered/layered architecture is a guideline (or software design pattern), therefore you will find implementations of the guideline will vary depending on interpretation, specific application use cases/requirements and frameworks that are available to the developer. This is even the case within the context of a single language, such as vb.net. It would be wrong to assume there is one "correct" implementation, but some are better than others.

Whilst very detailed and not providing direct code samples, the Microsoft Patterns and Practices are a good reference for architecting .net applications. There is an in-depth discussion of layering strategies and choosing the right one for your scenario here: http://msdn.microsoft.com/en-us/library/ee658109.aspx. It may help reveal that out of the samples you already have, one is better for your use case.